Error parsing the GET/POST data stream when trying to login to https

18User3_(Delete)_2154966

Help - some but not all users trying to log into our Livelink system via the Internet at a secure address (https)are receiving the following message:Error parsing the GET/POST data stream.Please try again. If the problem persists, contact your Livelink administratorOnly getting this when trying to loginHas anyone experienced this or resolved it? We are using Livelink 9.1 SP2